Accession Number : ADA320982

Title :   Radar Studies of Aviation Hazards: Part 3 Frontal Structure Studies.

Descriptive Note : Scientific rept. no. 3,

Corporate Author : HUGHES STX CORP LEXINGTON MA

Personal Author(s) : Harris, F. I. ; Smalley, David J. ; Tung, Shu-Lin ; Bohne, Alan R.

PDF Url : ADA320982

Report Date : 15 JUL 1996

Pagination or Media Count : 33

Abstract : Automated techniques have been developed to detect fronts and to extract their three-dimensional structure. Features such as surface frontal position, three-dimensional frontal surface, gradient fields, local wind estimates, and precipitation volume and mass are all monitored as a function of time. These structures and their changes have been related to the development of potentially hazardous weather. Further refinement and testing is required. Baroclinic fronts affect air terminal operations with a variety of weather events, such as abrupt wind shifts, enhanced wind speeds, and accompanying turbulence. Precipitation produced by frontal forcing can be intense and cause flooding. Temperature changes can be abrupt and when combined with precipitation can result in precipitation type changes in non summer months. For these reasons, the detection and forecasting of fronts is a major concern of weather forecasting services. Fronts are zones of transition in the temperature and wind fields and their intensity is usually assessed in terms of the magnitudes of the temperature changes and associated wind velocities. Cold fronts, especially, are noted for sharp changes in both temperature and winds. In addition, associated localized intense convection will enhance these fields and may cause severe weather. Fronts always occur in pressure troughs and will always have localized vorticity and convergence maxima. Therefore, monitoring vorticity and divergence in real time could provide useful diagnostic and prognostic information. Single Doppler radar cannot measure these fields individually. However, the radial velocity fields include contributions from these fields and can, therefore, be useful in the detection and monitoring of the fronts and associated phenomena.

Descriptors :   *HAZARDS, *DOPPLER RADAR, *METEOROLOGICAL RADAR, *WEATHER FORECASTING, *AVIATION SAFETY, *FLOOD CONTROL, *THUNDERSTORMS, ALGORITHMS, TEMPERATURE, VOLUME, AUTOMATION, DETECTION, MONITORING, REAL TIME, STRUCTURES, CONVECTION, TURBULENCE, VORTICES, TERMINAL FLIGHT FACILITIES, ESTIMATES, AERONAUTICS, THREE DIMENSIONAL, PRECIPITATION, SHIFTING, WIND VELOCITY, TRANSITIONS, SUMMER, GRADIENTS, SHARPNESS, COLD FRONTS, RADIAL VELOCITY.

Subject Categories : Meteorology
      Active & Passive Radar Detection & Equipment

Distribution Statement : APPROVED FOR PUBLIC RELEASE